Vehicle tire



' Oct. 16, 1923. 1,470,726"

E. GRATT VEHICLE TIRE Filed- April 8 1920 WITNESSES //\/VENTO/I2. 5 L f ATTOQNEKE/Q Patented st. 16, 1923.

EMIL GRATT, 0F WATEBTOWN, WISCONSIN, ASSIGNOR T0 OSCAR C. 'WERTHEIMEE. 0F WATERTOWN, WISCONSIN.

VEHICLE TIRE.

Application filed April a, 1920. fierial No. 372,178.

To all whom it may connern Be it known that I, EMIL GRA'IT, a subject of Budapest, Hungary, and a resident of Watertown, in the county of Jefierson and State of Wisconsin, have invented new and useful Improvements in Vehicle lires, of which the following is a description, reference being had-to the accompanyin drawin s, which are a part of this spec cation. his invention has for its ob ect to pro vide a vehicle tire'ot the type containing a sponge rubber tire fillcr or inner tire, the purpose being to avoid friction-and consequent wear between the spon e rubber tire filler and the outer casing. ponge rubber tire fillers have usually been provided with a fabric surface to fit against the fabric linof the outer casing. The rubbing of the 1 fabric surface causes friction and wear and is inclined to heat the tire. To avoid these conditions the resent invention provides the fabric coverin of the tire filler with a layer of solid rub er of material thickness incorporated therewith to form a smooth surface having less friction with the fabric lining of the casing.

With the above and other objectsin view the invention consists in the vehicle tire as herein claimed and all equivalents.

Referring to the accompanying drawin s in which like characters of reference in icate the same parts in difierent views:

Fig. 1 is an elevation partly in section of a vehicle tire constructed in accordance with this invention; and

Fig. 2 is an enlarged transverse section through the tire and its rim.

In these drawings the inner tire is shown to be of sponge rubber and is made in accordance with the Huebner Patents Nos. 1,103,359 and 1,260,384 except that a single fabric covering 10 surrounds the sponge rubber core 11 and is contained within an outer wall of solid rubber 12 of material thickness.

The solid rubber 12 like the outer convolutions of the sheet rubber, which is rolled together to term the mass before vulcanizin is not provided with the volatile ingre ients that reduce the cellular structure of the interior and consequently the rubber inside of and surrounding the fabric 10 is solid or free from the openings or cells that characterize the interior.

In order that the ph sical characteristi of the tire filler may better w the method of forming the cellular body may be briefly described. This is made from a rubber compound to which certain volatile and preservative ingredients have been added. The volatile ingredients in the rubber when heated under suitable conditions tend to expand and form a cellular structure the cells of which are filled with a gas medium, and the preservative inients maintain the moist condition of the rubher after vulcanization and insures its life for an indefinite period. This central portion or core whether it is made up of a cylindrical roll of the compound in sheet form or is molded from a common mass is surrounded by one or more convolutions of sheet rubber not containing the volatile ingredients and then with the sheet of fabric and finallywith another sheet of rubber not containing the volatile ingredients.

The ends of the cylinder are then 'oined to' form an annulus which is place in a suitable mold so constructed as to be gas tight and suficiently strong to withstand the pressure generated during the subsequent treatment. The mold is placed in a,

vulcanizing drum and-subjected to heat by means of steam surrounding the mold.- Pr!)- rnarily steam under low pressure isadmitted and this pressure is radually increased in the manner describefi in the l-lluebner patents, until vulwnization is com leted, when the-mold is removed and permitted to cool.

During the initial steps of heating which precede the vulcanization, the volatile inedients of the rubber compound, consistmg of turpentine and ammonium carbonate, are transformed into as globules which expand and produce cells, the prolonged continuation of the heat at a point'below that required for vulcanization giving the evenly distributed volatile matter time to become fully expanded before the rubber compound sets.

By reason of the fact that no opportunity is given for the evaporation of the volatile ingredient between the tune of incorporating it in the rubber coin ound and the formation of the cylindrica body, such cylindrical body is of uniform cornsltion m5 throughout except that portion wich 18 next to the interior of the fabric and that portion which is outside of the fabric.

The outer casing 13 and the rim is may of the usual and standard he: nd th too inner tire or filler of cellular rubber with the rubber coated fabric covering vulcanized thereto is of the exact size required to fill the casing when secured to the rim and to maintain the casing in a condition equivalent to the nroperinflation of an inner tube. The solid rubber lining for the fabric covering forms a strong binder between the -lebric and the cellular rubber core while the solid rubber coating on the outside of the fabric forms a smooth frictionless surface to fit the fabric coated wall cf the outer casing.

What I claim as new and desire to secure by Letters Patent is:

In a vehicle tire an outer casing, a tire filler fitting therein and comprising a sponge rubber core surrounded by a rubber coated fabric covering,' the rubber next to the fabric coating on the inside and outside EMIL GRATT. 

